Improvement in safety-valves



Patented Nov. 22, 1870.

'Au-ANCONA SAFETY VALVE.

ASTLEY COOPER ANCONA, Oh1` EVAN-SVILLE, INDIANA.

Letters Patent No. 109,483, dated November 22, 1870.

IMPROVEMENT IN SAFETYVALVES.

The Schedule referred to in these Letters'latent and'making part of thesame.

improved- Safety-Valve, ot' which the'thllon-'ng is a .specificationNature and Object of thallia-cation.

My improved safety-valve consists of a steam-chest having two s'eats,andv containing two loaded valves which, when in contact with theirrespect-ive seats, are in steam-tight contact with each otherbut which,when yielding to tho pressure of the steam, .will be separated from cachother simultaneously Vwith their movement from their seats,'all of whichwill bc iully explained hereafter'. i

My invention also consist-s in cert-ain peculiarities, fully describedhereafter,I in the construction offthe valve.

-'The object of my invention has been to produce safety-valve which thesteam can act upon and. open when it exceeds the proper pressure, butwhich it will he impossible for any one to gainaccess to and over.

load, or otherwise tamper with. without first 'entering the boiler.Description of the Accompanying Drawing.

Figure 1 1s a vertical section of my improved-safetyvalve as it appearswhen closed;

Figure 2, the same as it appears when open;

Figure 3, an exterior view of the valve-chest; and

Figure 4, aL plan view o i one otl the valves.l

General Description.

' A represents part of Athedome-'eap of'a locomotive boiler, and into'this cap is fitted and secured a tube,l rl, terminating at the top in ahollow ilange vor collar, b, which bears ou the dome-cap, and which hasopenings, 'e, in its edge, and openings, f f, in the -top` The`valve-spindle B passes through and is guided by the topof the tube a,the spindle being, in -the present instance, connected toa leven. C,-which has its fulcrum on a stud, D, secured in the dome.

The valve-chest is composed in thc present instance ot' theabove-mentioned tube a, the annular piece E, the intermediate ring F,and the cup G.

The annular piece E serves as a nut to secure the tube a in its place,and its lower edge is secured to the upper end, and the cap G- to theloiver end of the intermediate ring F, as-clearly shown in the drawing,the said iing having lateral openings, h h.

Y Upper and lower valves, H and I, are iitted loosely to the lowerportion B' of the valve-spindle, the seat for the upper valve being onthe top of the intermediate ring F, and that for the lower valve on theunder edge of thel said rino.

Each valve consists of a hollow cylinder having a;

perlbrated partition, -m in, through which the spindle passes, a collar,n, on the-said spindle, intervening bctween thel valves, but notpreventing them fromv being .brought into steam-tight cont-act witleaclrother.

Between thc' upper valve H and a nut, J, on the spindle, i'ltcrvenes aspiral spring, K, and between thelower valve and a nut, J on thespindle, intervencs u similar spring, lK', there being beneath the nut Ja suitable jam-nut, J'`.

.A jam-nut, l), also hears on thc nut J, and into4 this nut L screwedthe uppcl'. portion B ot' the valve-spindle.

lly means ofthesc nuts,o and.l',thc springs K and K' can he adjusted to.resist any pressure of steam may he. decided. on.A

lhc tendency oi' the. springs K and K' is to maintain the valves notonly in steam-tight 'contactwith each other, hut also in Contact withtheir respective seats, and they will remain in thiscondition so long asthe steam does 'not exceed the pressure which. the valves havehoenadjusted to resist, by thc nuts J and J.

' 1It will bc seen that there is a narrow annnlarspace, p, vbetween thevalves and the ring F of the chest, apd, consequently, that there is acorrespondingly limited annular arcanieachvalve exposed to the steaniwhich enters the chest through the latcral openings h l1.. When thesteam exceeds the proper pressure it will act-.on 'these limited. areasof the valves and force them-apart, and f'ronl their seatssimultaneously.

\Vhatever lnay he the distance to which each valve is removed from itsseat it will be exactly half the distance' to which Jthe valves arcseparated from cach other; hence there will be agi'ree passage for thesteam in three directions from the openings h into the tube a-inonedirection, between the upper valve H and its seat; in another direction,between the two valves, and

-thencc through the openings m met' the upper valve and in a thirddirection, between the lower Avalve and its scat, and'thencc through theopenings m m of the two valves, the steam inully escaping through theopenings c eand -jf j' of the hollow liange b. f

It will be impossible for any one to gain accessto y and overload andotherwise tamperwith the valves without first entcriug thestcamdome,rfor the lever 0,011 the outside ot' the dome, has nofunctions vto perform as regards the valves, itmcreiy enables theattendant engineer to determine whether the valves are in proper workingorder. It' he eievates the lever vv11e must necessarily raise thc valveH and permit the steam to escape, audit' he depresses the lever he mustdcpressfthc valve I with a like result, so that no ma- 1 1ipulation ofthe lever Acanv disturb the proper flinctions ot' the valves.

Even if the tube a .of the valve-chest was open at the top it would bedicnlt tocontrive an instrument by which the valves could be eectuallytampered 'with or overloaded, the weighting of the upper valve would notdisturb-the functions of the lower valve; but the 'introduction of anyavailable instrument is rendered next to impossible by the hollow flangeI),

vaswill be readily understood without explanation. v

The very limited area of the valves exposed to the action of the steam,enables me to use light and delicate springs, K and K of sneh smalldimensions that they cannot interfere with the free passage of steamthrough thevalves.

In so-calledlock-up safety-valves reliance is placed 'upon' locks asa'lueans of preventing access to the valves, but these locks beingexposed areat all times liable to be picked or broken.

My improved safety-valve, however, being con tained within the boiler,and being inaccessible from the extelior of the same, is always lockedby tbe boiler itself'.

Although I have referred to my improved safetyvalve as applied to alocomotive boiler, it will be evident that it canlbe adapted tostationary and marine boilers, and although I have shown the steam-chestof the safety-valve as constructed in a peculiar manner of the threepieces E, F, and G, it will be apparent to any engineer that it is notnecessary to adhere toV this plan in all case, although I prefer it onaccenni of its simplicity.

Claims.

1. A safety-valve, consisting of asteam-chcst having two seats andcontaining two loaded valves, which,

when in contact with their respective seats, are in steam-tight contactwith each other, butwbich, when yielding to the pressure of the steam,will be separated from each other simultaneously with their movementi'om their seats, all ,substantially as herein set forth.

2. The combination of the two valves H and I, the springs K and K', andspindle B. and its collar n, and adjusting nuts J and J 3. Thecombination of the said valves, spindle B B', itscollar n, and the toylever C, Ior its equivalent.

, 4. The tube a, having at the top a hollow enlargement or flange b,with openings f for tbe passage of' steam and a central opening for.the' passage of a spindle B, and at the lower end threads for thereception of the piece or nut E, as set forth.

5. The steam-chest, composed of the pieces E, F, and G, substantiallyas'` described.

(i. lhe said steam-chest in combination with the tube a, fitted to thedomo-cap of a locomotive or shell of" a boiler, as set forth.

In testimony whereof l IV have signed my name to this specilication inthe presence nt' two subscribing witnesses.

ASTLEY G. ANCONA.

Witnesses:

WM. H. H. Minnen, .TonN IfonnANen

